AB0804 THE PERFORMANCE OF ACR 1990 AND ACR/EULAR 2022 CRITERIA IN THE DIAGNOSIS OF GPA AND EGPA
Authors: P. Migliorini, L. Puccetti, M. Mantellassi, M. Moretti, A. Tavoni, C. Baldini
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> ANCA-associated vasculitis (AAV) are systemic disorders with involvement of multiple organs that may lead to severe damage. An early diagnosis and often an aggressive treatment is necessary to preserve organ function, but the diagnosis can be difficult at disease onset when non-specific symptoms are predominant. To address this issue, classification criteria have been developed in 1990 and recently updated. <h3>Objectives</h3> To evaluate the performance of ACR 1990 and ACR/EULAR 2022 criteria in the diagnosis of GPA and EGPA. <h3>Methods</h3> Patients with certain or suspected diagnosis of EGPA and GPA, followed in the Rheumatology and Clinical Immunology units, have been selected for the study. Concordance has been evaluated by means of the K Cohen coefficient. <h3>Results</h3> Out of 50 patients with the diagnosis of GPA, 36 (72%) fulfill the ACR 1990 criteria and 41 (82%) the ACR/EULAR 2022 criteria. Out of 31 patients with the diagnosis of suspected GPA, 17 (55%) fulfill the ACR 1990 criteria and 16 (52%) the ACR/EULAR 2022 criteria. Concordance is low (K=0,1). Analyzing discordant cases, 14 patients positive only for 1990 criteria have lung involvement and in half of the cases renal involvement. Eighteen patients positive only for 2022 criteria have anti PR3 ANCA, one third nasal involvement, one third lung involvement. This reflects the higher weight of pathology, renal and lung involvement in 1990 criteria, the weight of ANCA positivity and upper airway involvement in 2022 criteria. Out of 40 patients with the diagnosis of EGPA, 13 (33%) fulfill the ACR 1990 criteria and 36 (90%) the ACR/EULAR 2022 criteria. Out of 30 patients with the diagnosis of suspected EGPA, 1 (3%) fulfill the ACR 1990 criteria and 19 (63%) the ACR/EULAR 2022 criteria. Concordance is low (K=0,13). Analyzing discordant cases, 18 patients positive only for 2022 criteria have asthma and hypereosinophilia and in half of the cases nasal poliposis. This reflects the higher weight of asthma and hypereosinophilia in 2022 criteria. <h3>Conclusion</h3> These data clearly indicate a higher sensitivity of the ACR/EULAR 2022 criteria, that take into account ANCA detection by the currently available sensitive and specific techniques. On the other hand, the data confirm that classification criteria can be applied only to well selected cohorts of patients, when a careful clinical and laboratory workup has excluded other diagnosis and suggested a systemic vasculitis. <h3>References</h3> [1]Masi AT et al. The American College of Rheumatology 1990 criteria for the classification of Churg-Strauss syndrome (allergic granulomatosis and angiitis). <i>Arthritis Rheum</i>. 1990;33(8):1094-1100. [2]Leavitt RY et al. The American College of Rheumatology 1990 criteria for the classification of Wegener's granulomatosis. <i>Arthritis Rheum</i>. 1990;33(8):1101-1107. [3]Ponte C et al. 2022 American College of Rheumatology/EULAR classification criteria for giant cell arteritis. <i>Ann Rheum Dis</i>. 2022;81(12):1647-1653. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.